How much does a 1.50 to 1.99ct F SI1 natural radiant diamond cost?

As of October 2026, 1.50 to 1.99ct F SI1 natural radiant diamonds typically cost £4,225 GBP to £11,002 GBP, with a median price of £6,752 GBP. There are currently 142 diamonds matching this specification available across retailers.

Where can I find the best price on a F SI1 radiant diamond?

About 37% of these diamonds are available at multiple retailers, with an average price spread of 47%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct F SI1 Natural Radiant

Quick answer

As of October 2026, there are 142 natural radiant diamonds with F colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run £4,225 GBP to £11,002 GBP, with a median of £6,752 GBP. At least 62 retailers stock this exact specification, and 37% of the stones appear at more than one of them, with an average price spread of 47%. Half of all listings fall between £3,208 GBP and £5,117 GBP per carat. The same specification in lab grown form lists at a median of about £328 GBP per carat. Over the last 30 days the median price moved -2.2% and the number of listings moved +17.9%.

Three of the best scored stones at this specification right now:

Caratlytics Diamond Price Index, September 2026: natural diamonds at 2,335 USD per carat and lab-grown at 443 USD per carat, a natural to lab ratio of 5.3 to 1. Radiant natural stones in the index: 3,091 USD per carat, +13.2% month on month. See the full index release

Figures come from current listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: October 2026

Available

142

Lowest Price

£2,675 GBP

Highest Price

£17,759 GBP

Average Price

£7,314 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

36.8%

Price Spread

47.1%

30-Day Price Trend

-2.2%

30-Day Supply Change

+17.9%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$5,394/ct

10th Percentile

$3,506

Median

$5,394

90th Percentile

$8,182

Score Distribution

319 diamonds scored across 4 quality tiers

Excellent

41 (12.9%)

Very Good

71 (22.3%)

Good

77 (24.1%)

Average

130 (40.8%)

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Consider Instead

Save money without compromising on what matters. These alternatives are visually similar but cost less.

F SI2SI2 inclusions are not visible without magnification

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Lab-Grown F SI1Same specifications, lab-grown origin

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Related Specifications

D IF D VVS1 D VVS2 D VS1 D VS2 D SI1 E IF E VVS1 E VVS2 E VS1 E VS2 E SI1 F IF F VVS1 F VVS2 F VS1 F VS2 F SI1 G IF G VVS1 G VVS2 G VS1 G VS2 G SI1 H IF H VVS1 H VVS2 H VS1 H VS2 H SI1 I IF I VVS1 I VVS2 I VS1 I VS2 I SI1